fix(ux): misc ux issues

[ankush]

• arbitrary hardcoded number for sorting 9999 replaced with float('inf') 🤡
• two way alternative item validation both item should have "allow alternative item" checked if two way is checked.
• don't show blocked suppliers in autocomplete. (at least wherever supplier query is used, e.g. PO, PI)
• make Work Order qty 1 by default so required items table can be populated on selecting item.

[ankush]

raw query - not new, just moved.

[codecov]

Codecov Report

Merging #28111 (91cae1c) into develop (e0cf45e) will decrease coverage by 0.06%.
The diff coverage is 10.00%.

@@             Coverage Diff             @@
##           develop   #28111      +/-   ##
===========================================
- Coverage    55.12%   55.05%   -0.07%     
===========================================
  Files         1255     1255              
  Lines        67929    67934       +5     
===========================================
- Hits         37448    37404      -44     
- Misses       30481    30530      +49     

Impacted Files	Coverage Δ
erpnext/controllers/queries.py	60.32% <ø> (ø)
...stock/doctype/item_alternative/item_alternative.py	0.00% <0.00%> (ø)
...ext/manufacturing/doctype/work_order/work_order.py	73.33% <100.00%> (ø)
erpnext/utilities/product.py	15.94% <0.00%> (-34.79%)	⬇️
erpnext/shopping_cart/product_info.py	32.35% <0.00%> (-20.59%)	⬇️
.../report/stock_projected_qty/stock_projected_qty.py	87.01% <0.00%> (-2.60%)	⬇️
...value/warehouse_wise_item_balance_age_and_value.py	92.59% <0.00%> (-2.47%)	⬇️
erpnext/stock/report/stock_ageing/stock_ageing.py	89.20% <0.00%> (-2.16%)	⬇️
...e/shopping_cart_settings/shopping_cart_settings.py	66.03% <0.00%> (-1.89%)	⬇️
...ctype/accounting_dimension/accounting_dimension.py	64.34% <0.00%> (-1.56%)	⬇️
... and 15 more